Learning objectives
- What is a biofilm
- How do biofilms form
- why are biofilms medically important
- Role of infection in cystic fibrosis
- Importance of infection control in cystic fibrosis
What is a biofilm (contrast with planktonic bacteria)
A biofilm is a community of bacteria comprised of multiple groups of bacteria existing withing extracellular polymeric substances that adhere to each other and or a surface.
Importance of biofilms in medicine
Biofilms are a ver important virulence mechanism. the Ectracellular suybstances odder protection from antimicrobials, host defences, and other environmental stressors. This is so successful it is present id ~80% of all microbial infections in humans involve biofilms, It is the prodominant mode of bacterial growth in chronic infections.
Biofilms: complex structures of bacteria embedded in matrix
Biofilms are not a simple unilayer structure it is complec multilayered structure with nutrient channels microcolonies and heterogenous bacterial populations. Often there are nutrient differentials forming bacterial crossfeeding
Biofilms are like fortresses
Biofilm antibiotic tolerance
Biofilms are inherently more tolerant to antimicrobials compared to planktonic cells. this is because of a few factors, there is reduced penetration of antimicrobials into a biofilm, often due to lower nutrient rates slow growth, making antimicrobials less effective. There are also persister cells, which are cells that are in spore form,
Biofilm intercell communication
bacterial constantly produce autoinducers which, when sensed in large quantities by a bacteria triggers certain gene expression for management of scarity
Biofilms in CF
Treatment of clinical biofilms
Remove ant biofilm infected objects Antimicrobial treatment Early: aggressive Chronic: prolonged or suppressive
Refresher of CF
CR related lung disease
pseudomonas infection in cystic fibrosis
P aeruginosa adapts in host over time
Treatment of infection in cystic fibrosis
nontuberculous mycobacteria in CF